JPH06129866A - Calibration value determining device for vehicle sensor - Google Patents

Abstract

PURPOSE:To provide a new system for determining a calibration value for the detected value of a sensor for detecting the moving condition of a vehicle while it is making a straight drive by simultaneously utilizing a technique for navigation and a fact that the part between the turning points of the inflow road and the outflow road of the main roadway of a highway is substantially straight. CONSTITUTION:The present location of a vehicle on a road map is detected by a GPS system navigation device, and it is determined whether a vehicle is driving in the substantially straight section of the main roadway of a highway or not by utilizing a memory of road information (S1 to S4). When a vehicle is driving in the substantially straight section, it is determined whether the lane change of a vehicle is caused by monitoring a winker switch and a steering angle (S6), and when the lane change is not yet caused, the detected values of a steering angle sensor, a yaw rate sensor and the like are fixed for a calibration value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects a motion state quantity of a vehicle and determines a calibration value of a detection value of a sensor, the detection value of which is affected by turning of the vehicle in a state where the vehicle is traveling straight ahead. A calibration value determination device for a vehicle sensor.

[0002]

2. Description of the Related Art A conventional example of a calibration value determining device for a vehicle sensor is disclosed in Japanese Patent Application Laid-Open No. 60-15270 of the present applicant. This is to determine whether or not the vehicle is in a straight traveling state from the mutual relationship between the wheel speeds of the left and right wheels, and if so, determine the calibration value of the steering angle sensor as the vehicle sensor. .

[0003]

By the way, recently, it is becoming popular to mount a navigation device on a vehicle. Here, the navigation device is used to detect the current position of the vehicle on the road map and display it to the driver.

On the other hand, an expressway generally has a main line, an inflow path to the main line, and an outflow path from the main line, as shown in FIG. The outflow route is branched from the main line,
Of the main lines of this expressway, the traveling section sandwiched between the branch point of the inflow path and the branch point of the outflow path corresponding to the inflow path is generally a substantially straight line.
Such a substantially straight section exists, for example, in an interchange on a highway, a parking area, or the like. For example, the radius of curvature of a substantially straight section at an interchange on a highway is about 3000 m or more on most highways,
Even the smallest place is about 1000m. However, the term "highway" as used herein means a highway such as the Tomei Expressway, the Meishin Expressway, or the Tohoku Expressway, and does not mean an urban expressway such as the Shuto Expressway or the Hanshin Expressway.

It is therefore an object of the present invention to provide a new form of calibration value determination for vehicle sensors by combining the use of navigation techniques with the existence of substantially straight sections on highways. It is a thing.

[0006]

In order to solve this problem, the present invention provides a calibration value determination device for a vehicle sensor, as shown in FIG. 1, (a) showing the current position of the vehicle on a road map. In the substantially straight line section determination means 1 used by being connected to a navigation device for detection, the current position of the vehicle detected by the navigation device is the main track, the inflow path to the main track, and the main track. Of the main line of the highway that has an outflow path, and those inflow path and outflow path are branched from the main line,
To determine whether or not to belong to a substantially straight line section sandwiched by the branch point of the inflow path and the branch point of the outflow path corresponding to the inflow path, and (b) if the current position of the vehicle belongs to the substantially straight line section The calibration value determining means 2 for determining the calibration value of the vehicle sensor based on the determination is included.

The "calibration value determining means 2" here
For example, although it is possible to adopt a form in which the calibration value of the vehicle sensor is determined immediately when it is determined that the current position of the vehicle belongs to the substantially straight section, it is necessary to further improve the accuracy of determining the calibration value. In some cases, for example, the following format can be used.

That is, in general, the accuracy of determination is improved by making a straight-ahead traveling determination using a plurality of types of information, rather than making a straight-ahead traveling determination by using only one type of information. It is determined whether or not the vehicle motion state quantities such as the wheel speeds of the left and right wheels and the vehicle speed indicate that the vehicle is in a straight traveling state, and it is determined that the current position of the vehicle belongs to the substantially straight section, and The calibration value of the vehicle sensor can be determined only when it is determined that the motion state quantity of 1 indicates that the vehicle is traveling straight ahead. Further, it is determined whether or not the operation state of the blinker switch, the brake operation member, etc., which reflects the driver's intention to operate, indicates that the vehicle is in a straight traveling state, and the current position of the vehicle belongs to the substantially straight section. It is also determined that the calibration value of the vehicle sensor is determined only when it is determined that the driver's operation status indicates that the vehicle is in a straight traveling state.
It is also possible to combine these two formats.

[0009]

The vehicle according to the present invention is based on the fact that the navigation section is used and the traveling section between the inflow and outflow branch points of the main line of the highway is substantially straight. In the calibration value determination device for the sensor, the current position of the vehicle detected by the navigation device by the substantially linear section determination means 1 is
It is determined whether or not the vehicle belongs to the substantially straight line section of the main line of the expressway, and the calibration value determining unit 2 determines that the current position of the vehicle belongs to the substantially straight line section.
A calibration value for the vehicle sensor is determined.

[0010]

As described above, according to the present invention, it becomes possible to determine the calibration value for the vehicle sensor by a format different from the conventional one, and the range of selection of the format of the calibration value determining device is expanded. The effect is obtained.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle controller including a calibration value determining device for a vehicle sensor according to an embodiment of the present invention will be described in detail below with reference to the drawings.

The calibration value determining apparatus according to the present embodiment will be roughly described. First, the motion state of the vehicle (vehicle speed, vertical acceleration of wheels, that is, road surface unevenness), the driver's steering state (steering angle), and navigation. Based on the current position of the vehicle detected by the device, it is determined whether the vehicle is traveling on the main track of the highway. If it is determined that the vehicle is traveling on the main track of the expressway, it is determined whether the vehicle is traveling on a substantially straight section of the main track based on the road information stored in advance. . Here, the “substantially straight section” means a portion of the main line at an interchange on a highway, which is sandwiched between a branch point of an inflow path and a branch point of an outflow path corresponding to the inflow path. If it is determined that the vehicle is traveling in a substantially straight section, it is determined whether or not the vehicle has been changed by the driver based on the driver's intention to steer (steering angle, blinker switch). If it is determined that the vehicle is not being driven, it is determined that the vehicle is in a straight traveling state, and the calibration values of the steering angle sensor, the yaw rate sensor, and the lateral G sensor are determined. In the straight running state, the steering angle of the steering wheel, the yaw rate of the vehicle body, and the lateral acceleration should be 0, respectively. Therefore, the steering angle θ, the yaw rate YAW, and the lateral direction detected by the sensors in the straight running state. The values of the acceleration GY are the calibration values θ _C , YAW _C , and GY _C , respectively.

In this embodiment, the straight-ahead traveling determination is performed using the detected steering angle θ, and the calibration value of the steering angle θ is determined in the straight-ahead traveling state. Since the accuracy required for the traveling determination is not so high, the accuracy of the straight traveling determination does not decrease due to the error in the steering angle θ.

In order to carry out straight running determination and sensor calibration as described above, the calibration value determining device, as shown in FIG. 2, includes various sensors and switches 10, etc., and a road type determining computer 20 for calibration values. Decision computer 3
It is configured by being connected to the input side of 0.

The various sensors and the switch 10, etc. are specifically the steering angle sensor 10, the vehicle speed sensor 12, the vertical G sensor 14, and the turn signal switch 16. The steering angle sensor 10 detects the steering angle θ of the steering wheel. The vehicle speed sensor 12 detects the vehicle speed, which is the traveling speed of the vehicle. The vertical G sensor 14 detects the vertical acceleration of the wheels from the change in the damping force of the shock absorber that connects the wheels to the vehicle body.
The turn signal switch 16 is operated by the driver to blink the turn indicator light of the vehicle.

A navigation device 40 and a road information memory 42 are connected to the input side of the road type determination computer 20. The navigation device 40 detects the current position of the vehicle on the road map by the GPS method, receives the signal from the artificial satellite with the receiver 46, and stores the reception result and the road information memory 42 in advance. The current position of the vehicle on the road map is detected based on the relationship between the current position and the road.
The navigation device 40 also corrects the vehicle position based on the signal from the artificial satellite by appropriately performing map matching. The navigation device 4
It is possible to implement the present invention in which 0 is a format in which the current position of the vehicle is detected using a wheel speed sensor, a geomagnetic sensor, a road beacon, or the like.

The road information memory 42 also stores the relationship between the position on the road map and the type of road (highway, national road, prefectural road, main local road, etc.). Further, with regard to expressways, the positions of substantially straight sections at each interchange are also stored.

The calibration value determination computer 30 determines its R
A calibration value determination routine represented by a flowchart in FIG. 3 is stored in the OM, and the CPU thereof executes the calibration value determination routine so that the straight running determination and the calibration value determination described above are performed. ing. The contents of this calibration value determination routine will be described below.

This routine is repeatedly executed at regular intervals while the calibration value determination computer 30 is powered on. Specifically, first, in step S1 (hereinafter, simply referred to as S1; the same applies to other steps), the current road type is fetched from the road type determination computer 20, and the vehicle is determined based on the navigation information. It is determined whether or not the vehicle is currently traveling on an expressway. If the vehicle is not traveling on the highway, the determination is NO
Then, one execution of this routine ends, but if the vehicle is traveling on a highway, the determination becomes YES, and the process proceeds to S2.

In S2, the current vehicle speed is read from the vehicle speed sensor 12, and a set of the current vehicle speed and the past vehicle speed (stored in the RAM) is stored for a fixed time (for example, 5).
The average value of a plurality of vehicle speeds within () is calculated as the average vehicle speed. Further, the smallest vehicle speed among the plurality of vehicle speeds is calculated as the lowest vehicle speed. Furthermore, the present steering angle θ is read from the steering angle sensor 10 and is a set of that and the past steering angle θ (also stored in the RAM), which is the most of the plurality of steering angles within the above-mentioned fixed time. The larger one is calculated as the maximum steering angle. Furthermore, the current vertical acceleration is read from the vertical G sensor 14, and a set of the past vertical acceleration (also stored in the RAM) and the tendency of fluctuation of the vertical accelerations within the fixed time is determined. To be done.

Further, in S2, whether the average vehicle speed is 70 km / h or more, the minimum vehicle speed is 60 km / h or more, and the maximum steering angle is 60 deg or less,
It is determined whether the vertical acceleration fluctuation is small and whether the road is a bad road or a bad road. Then, when all of the four partial determinations are YES, it is determined that both the motion state of the vehicle and the driving state of the driver match the running of the main track of the expressway. Assuming that none of the four partial determinations is YES this time, the overall determination in S2 is NO,
One execution of this routine ends. On the other hand, assuming that these four partial determinations are YES this time, the determination becomes YES, the process proceeds to S3, and it is determined that the vehicle is currently traveling on the main line of the highway. It

The S2 is provided for the following reason. That is, in S1, it is determined whether or not the vehicle is traveling on the highway only from the navigation information (only from the type of the current road). Therefore, even if it is determined that the vehicle is traveling on the highway here. The vehicle is not always traveling on the main line of an expressway, but may be traveling on an inflow path or an outflow path branched from the main line. Therefore, this S2 is provided in order to determine whether or not the vehicle is traveling on the main line of the highway by excluding the latter case.

If it is determined in S3 that the vehicle is currently traveling on the main line of the expressway, then in S4, the vehicle is currently running on the straight line of the main line via the road type determination computer 20. It is determined whether or not the vehicle is traveling in the section. That is, while the vehicle continues traveling on the main track, it is waited for the vehicle to reach the substantially straight section.
Assuming that the real straight section has not been reached this time,
The determination is NO, and one execution of this routine ends.

After that, when the vehicle reaches the substantially straight section while the steps S1 to S4 are repeated many times,
The determination in S4 is YES, and in S5, it is determined that the vehicle is traveling in a substantially straight section.

Then, in S6, it is determined whether or not the vehicle has been changed lane. Specifically, the turn signal switch 16 is not operated, and
It is determined whether the steering angle θ is smaller than 9 deg. This time, assuming that these two conditions are not satisfied at the same time, the determination is NO, and it is determined in S7 that the vehicle is undergoing a lane change. On the other hand, the turn signal switch 16 is not operated and the steering angle θ
Assuming that is smaller than 9 deg, the determination in S6 is YES.
Then, in S8, it is determined that the vehicle is traveling straight ahead,
Subsequently, in S9, the calibration values θ _C , YA W _C and GY _C are determined as described above. Thus, one execution of this routine is completed.

As shown in FIG. 2, an antilock computer 50 and a rear wheel steering computer 52 are connected to the output side of the calibration value determination computer 30.

The anti-lock computer 50 is a computer for controlling the brake pressure of each wheel so that the wheels do not lock when the vehicle is braked. The anti-lock computer 50 has a longitudinal G sensor 54, a lateral G sensor 56 and a wheel speed sensor on the input side. 58 is connected to the calibration value determination computer 30, while an actuator 60 is connected to the output side. Front and back G
The sensor 54 and the lateral G sensor 56 respectively detect the longitudinal acceleration GX and the lateral acceleration GY generated in the vehicle body, and the wheel speed sensor 58 detects the wheel speed VW which is the rotation speed of each wheel. The actuator 60 electrically controls the brake pressure of each wheel.

The anti-lock computer 50
Determines based on the longitudinal acceleration GX, the lateral acceleration GY, and the wheel speed VW whether or not the antilock control needs to be executed for each wheel, and if so, the longitudinal acceleration G
Based on X, the lateral acceleration GY, and the wheel speed VW, the target control characteristic of the antilock control is determined for each wheel, and the actuator 60 is controlled so that the target control characteristic is realized.

Further, the anti-lock computer 50 is
The calibration value GY _C is input from the calibration value determination computer 30, the lateral acceleration GY _in detected by the lateral G sensor 56 is calibrated using the calibration value GY _C , and it is used as the lateral acceleration GY. That is, the true lateral acceleration GY is acquired using the formula GY = GY _in −GY _C , and the anti-lock control is performed using this.

On the other hand, the rear wheel steering computer 52
Is a computer for controlling the steering angle of the rear wheels of the vehicle so that the traveling direction and the direction of the vehicle body match each other.
On the input side, the steering angle sensor 10, the vehicle speed sensor 12, the calibration value determination computer 30, and the yaw rate sensor 64 are provided.
Are connected to each other, while the actuator 66 is connected to the output side. The yaw rate sensor 64 detects the yaw rate YAW generated in the vehicle body, and the actuator 66 electrically controls the steering angle of the rear wheels.

Then, the rear wheel steering computer 52 determines the target value of the rear wheel steering angle using the formula δ = K ₁ · θ + K ₂ · YAW so that the target rear wheel steering angle is realized. The actuator 66 is controlled. However, in this equation, “K ₁ ” is a variable gain depending on the vehicle speed, while “K ₂ ” is a yaw rate feedback gain variable according to the vehicle speed.

Further, the rear wheel steering computer 52 receives the calibration values θ _C and YAW _C from the calibration value determining computer 30, and the steering angle sensor 10 and the yaw rate sensor 6 are input.
The steering angle θ _in and the yaw rate YAW _in detected by 4 are calibrated using the calibration values θ _C and YAW _C, and they are used as the steering angle θ and the yaw rate YAW. That is, to acquire the true steering angle theta with θ = θ _in -θ _C becomes equation to obtain the true yaw rate YAW using YAW = YAW _in -YAW _C becomes ## wherein the rear wheels using them It controls the steering angle δ.

As is clear from the above description, in the present embodiment, the calibration values of the steering angle sensor 10 and the like are determined only when the vehicle is traveling in a substantially straight section.
The calibration value is determined when the vehicle is truly in a straight traveling state, and the effect of improving the accuracy of determining the calibration value is obtained.

Further, in the present embodiment, it is determined whether or not the vehicle is in a straight traveling state by considering not only the navigation information but also the motion state of the vehicle and the driving state of the driver. The unique effect that the accuracy of straight running determination is improved is also obtained, and this is also an effect that the accuracy of determining the calibration value is improved.

Further, in the present embodiment, the control accuracy of the anti-lock control device and the rear wheel steering control device connected to the calibration value determining device is also improved in addition to the effect of improving the accuracy of determining the calibration value. You can also get the unique effect.

As is apparent from the above description, in this embodiment, the road type determining computer 20 and the road information memory 42 cooperate with the portion of the calibration value determining computer 30 that executes S1 to 5 of FIG. Then, the portion of the calibration value determination computer 30 that executes steps S6 to 9 of the "substantially straight line section determination means 1" of the present invention corresponds to the "calibration value determination means 2" of the present invention. It constitutes one aspect.

Although one embodiment of the present invention has been described in detail with reference to the drawings, various modifications and improvements can be made based on the knowledge of those skilled in the art without departing from the scope of the claims. The present invention can be implemented in such a manner.

[Brief description of drawings]

FIG. 1 is a block diagram conceptually showing the structure of the present invention.

FIG. 2 is a system diagram showing a vehicle control device including a calibration value determination device according to an embodiment of the present invention.

FIG. 3 is a flowchart showing a routine used by a computer of the calibration value determination device.

FIG. 4 is a diagram for explaining a configuration of a portion of the expressway which is closely related to the present invention.

[Explanation of symbols]

 10 Steering angle sensor 20 Road type determination computer 30 Calibration value determination computer 40 Navigation device 42 Road information memory

Claims (1)

[Claims] 1. A calibration value of a detection value of a sensor which detects a motion state quantity of a vehicle and whose detection value is affected by turning of a vehicle,
A device for determining when a vehicle is traveling straight ahead, which is a substantially straight line section determination means used by being connected to a navigation device for detecting the current position of the vehicle on a road map, the navigation device The detected current position of the vehicle has a main track, an inflow path to the main track, and an outflow path from the main track, and the inflow path and the outflow path are branched from the main track, respectively. Among the main lines of the existing highway, it is determined whether or not it belongs to a substantially straight line section sandwiched by a branch point of the inflow path and a branch point of the outflow path corresponding to the inflow path, and Calibration value determining means for determining the calibration value of the vehicle sensor based on the determination that the position belongs to the substantially straight line section.